Heating furnace



H.A A. DREFFEIN` v1,757,707 HEATING FURNAG Filed uarcn so, 1928 :s sheets-sheet 1 Vay 6,' 1930.

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May 6, 1930.

H, A. DREFFEIN HEATINGFURNACE 5 Sheets-Sheet 2 Filed March 30, 1928 A Wh m.

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My'G, 1930.l H. A. DREFFglN n 1757707 i HEATING FURNAcE Filed March so, 192s s sheets-smet 3 Patented May Y6, 1,930-

UMTED STATeSPATfENr l `HENRY anREErEIN, or marcado, ILLINOISr y* man? :enfermer` FURNAG Appiieation "niet` Maren so, 1928.yseria1 in, 266,086."v y

through `Which such materials flow duringY the heating Whensubjected to high external temperatures by direct contact `With heating gases or the like, become ycoated orl internally caked with the material in ooked' condition and this coating frequently results in obstruct-l ing the Vflow o'fheat throughthe pipe to the fluid content and the pipes become overheated and break down-'or lsag causingshut downs and fires, as Welly as damaging the furnaces themselves. With a furnace embodyingmy invention, the heating gases of combustion'vvhen''de-` livered into the furnace chamber `do not directlyrcontact with the pipes butffloiv adjacent thereto during Which flow radiant heat is transmitted to the pipes serving to reduce the temperature of the heating gases which' are then passed around the pipes to be partly discharged through the exhaust ports and partly re-circulated with' the incoming gases,this

admixture of partially cooled gas WithV the 3 incoming gas at maximum temperature serving to partially reduce the temperature of the latter so that a more uniform temperature prevails throughout the ufurnace chamber.

i Another object resides in the process `of heating viscid materials or the like Which may be effectively practiced in the apparatusembodied in my invention; n f a Other objects Will be apparent fromV a read- 40' ing of the following specification. yIn the accompanyingfdrawings l' have illustrated one embodiment of my apparatus, 1n` WhlchV drawings:

Fig. l is a vertical longitudinalfsection` along the regular section linev l-lof Fig. 4L;y Fig. 2 is an end elevation of thesame, one

of the clean-out doors-beingshown as removed; l Y

Fig. 3 is a vertical section along the line 3 3 of Fig. 4;

openings, of Which there aretWo at each end Figtis aihorizontalsection along 'the-line fr 4 4:- ofFig.,1.v v y f 1 2 .Likejjy numerals `.refer to like (elements :throughout the drawings,` in Which islillustrated a furnace having the end VWalls ,10,v 1l, 55 the sidewalls l2, 13 and theroof 15 all con- `structedfof suitable refractory material held togetherloyVV buckstays fl, tie vrodsfl and the like., he roofl ispreferably"arched, as shovvnin Fig."3, forexalnple.V l' f In the bottom Aof thefurnaceisy provided a heating tunnel 2O divided into twoportions by the intermediate orcentrally disposed'partition 20a. yA Lburner opening or nozzle 21l is provided `in each end Wall at rthe ends'of tunnel 20 for the introductionof fuel, such as oil, gas, powderedcoa'l or the like, although it Willbe understood that any'suitable heating fuel fmayube utilizedandthe structure modified to accommodatethe use of such fuel. y- Combustion to a' greater or vless Vextent .takes place inthe tunnel `2O and an outlet 20b is provided'therefrom inthefloor of the 'heating' chamber of the furnace asillustrated .inFig 3,for example. Refractory blocks 75. or tile 26 areplaced at intervals across the l opening 2Ob to provide ports 27 for the heating gases from the tunnel 20. By v'shifting or varying the size of these blocks-or tile 26k the size ornumber of `the ports 27 may befvaried to produce thefh'eating effect'de'sired at 'dif-l ferent points in the furnace. Above the outlet 20b the furnace cham-ber is provided viv/ith a clear space 28, at eachside of which arecourses of pipe 3() arranged Vinigroups, each group in the formillustrated comprising a continuous conduit for thefmaterialto bel heated.' The end Walls are provided .With cutout portions l0?, 11a and in each.l of these inthe form illustrated, is located'a built-up plate 32 illustrated as formedof sections or units as shown in Fig. 3, for example', suitably lapertured for the passage of the ends of each run of pipe 30, the runs being connectedby headers 33 located outwardly vof therplates 32..` A clean-out door or cover plate 35 is mounted to cover the header ends of the pipes v ateach end of the furnace, these doors 35 'be- 1 in'ghinged at 35a (see Fig. 2) for readyaccess a 100 to the pipe ends for cleaning, inspection or the like. Y e

At each end of the furnace is also provided a hinged or sliding door 37 communicating with the clear space 28 just above the floor level for ready access to the interior of the furnace for adjustment, replacement or removalof lthe blocks 26; J y

At each side of the furnace beneath lthe lgroups of pipes and in the floor o f the heating chamber is providedra plurality of outlet ports 39. Beneath each set of theseports is located an exhaust tunnel 40. At itscentral 2Q iin both portions thereof.v The gases of- Cmbustion lbeing iinderspressiire flow up- Warlflly at substantial vvelocity through the outlet .20h into space' 28 rising toward the roof-15 0f the. furnace underpressure and MSO actuated'by the natural tendency ofthe heated Vgases vto rise; Duringthisiiow the gases are substantially out of contact With hpipes 30,-hut'transmit radiant heat thereto which transmission and the absorption thereof bythe pipes andthe material in the pipes lowers the temperature of suchy gases.

A s the gases rise inthe space 28L they expand. The -delivery vof suchy gasesthrough the ports 2Ob being at substantial velocity sets up an'inductive leffect at the lower portion of the furnace andthis in conjunction With the tendencyE of the'cooler gases at the top of the furnace/to fall, sets upa species of circulatory action. AThe outlets 39 being located at ornear-.the bottom of the furnace and adj acent the sideswthereof, contribute tothe down- Ward movement ofthe circulating gases and permit the exhaust of a portion of the gases of combustion, the remainder being re-circulated into admixture vrwith the VVincoming gases; The-arched'roof 15 may assist in the deflection of the gases toward the'pipes.v The` gates-or dampers42 are Y'adjustedto obtain the desired discharge ofgases andyasstated,

thati'pOr/ton thereof in'excess of the capacity; of the'outlet'openings 41 is induced or movedl transversely of the heating chamber adjacentjthe-bottom thereof to admix With the incoming gases of combustion. Being at va relatively lowered-temperature, the re-.circulatedgases in mixing with vthe incoming fresh gases also assistinlewering the temperature of the latter so that the relatively high maxii Afromlthe upper portion of the heating chamber. Y

,It Willbe noted that-a bank of tubesSO is provided at eachside of the Wall space 28 Kand interposed between .the incoming gases and the refractory Walls. .By this arrange- Vtmentithe radiant heat of the .incoming gases impinges upon the tubes before it: contacts With the masonry or refractory Walls. In this manner'the walls are subjected to a materially lesser heat andradiation losses are greatlycut down sothat the'economy vand ,eficiency of operation are much greater `than Would otherwise be the case. Atthe same time the inner tubes of each bank' aresubjected to radiant-heat lalone when vthe gases maybe at their highestand most destructive temperature andthis not onlyfpartially reduces this temperature, but eects a-saving of the'heat units in a desirable manner. Y The operation permits the use of heating gases at a 'higherinitial temperature and subjects thepipes and their contents to a more uniform-temperature throughout the heating chamber, so that by proper control of such temperature-the objectionable colrin'g effect and subsequent destruction of the pipes is obviated. Also none of the pipes are subjected .to a destructive concentrated contact of the incoming gases which are at maximum temperature.

- Thel construction'permits ready access to the header ends of the pipes for cleaning or replacement, Any suitable connection with a source of materials to be heated maybe made.` As this forms no integral part of mypresent invention', Ihave not illustrated the same in detail. l It Will be obvious that my invention may be modied and changed and Ido not Wish to be vrestrictedto the form shown and de-` be limited thereto duced by transmission of said radiated heat.,

whereby the tubes at said side will be sub` jected to the' 'effect of substantially only ra-V diant heat from the iniiowingfheating gases. `2. A process of heatingviscid materials, consisting inpassing said materials through spaced runs of pipe in a. heating chamber, in-

troducing heating gases at oneside of said pipes at'substantial-velocity` and out of direet contact therewith', subjecting said pipes at said side to unobstructed` radiated heat from saidgases and thereafter changing the direction` of flow of and circulating said gases around said pipes at the temperature as reduced by transmission of said radiated heat, and recirculating a "portion of said gases after passage around said pipes with the inv inflowing heating spaced from said supply means, whereby the' coming gases of combustion, whereby the tubes at said side will be subjected to the effect of substant-ially only radiant heatV from the gases. j

3. A heating furnace for viscid materia] having a heating chamber, circulating pipes in said chamber for Vthe passage of said ma-` terial, said pipes being spaced and arranged pipes of said group adjacent said clear space will be subjected to thev directradiant heat of the iniowing gases without contact therewith, and whereby said gases will subsequently flow downwardly through said pipes for heating thereof by convection. Y

4. A heating furnace.. for viscidmaterial, having a heating chamber, circulating pipes `in said chamber for the passage of said material, said pipes being arranged in a group f in spaced relation in such 'wise as to provide a clear space in said chamber and-means to supply heating gases `in a vertical direction, at substantial velocity to said space at vor near the bottom of said chamber whereby said pipes adjacent said clear space will be subj ected to the direct unobstructed radiant heat of the incoming gases supplied to saidaspace without contact therewith, said furnace 'being further provided with an outlet for said gases i ranged with respect to said pipes as to. cause spaced from said supplying meansand so arcirculation of said i gases downwardly and around said pipes.

5. A heating furnace for viscid material.

having a heatingchamber, spaced Vcirculation pipes for said material arranged in one portion of said chamber means to supply heating gases to said heating chamber in aV vertical direction at one side of said pipes, at substantial velocity and out of direct iminediate contact therewith., whereby said pipes adjacent the inflowing gases will be subjected to the direct radiant heat thereofwithoutcontact therewith, an outlet passage located beneath saidpipes andportscommunicating bey tween said heating chamber and said passage,

Je I.

to effect redirection of said gases 'and' a cir-y culation thereof through said pipes to heat thesame by'convection.` `Y

tion pipes forvr saidlmaterial arrangedVK in one portion .of'saidV chamber; means to supply heating gases to said Lheating chamber in a vertical direction at" one side of `said pipes at substantialvelocity, and out ofdirect immediate'contact therewith, whereby'said pipes l6. A heating furnace for j viscid materialV 4havinga heating chamber, spaced circulaadjacent the-inflowing gases will be subjected to the direct radiant heat thereof without-contactk therewith, anioutlet passage located fbeneath said. pipes and ports communicating between-said heating chamber and. said passage, said passage being providediwitlikan outlet port, toefect a redirection of said gases and acirculation thereof 'through said pipes to heat the same by convection, and means to regulate the sizeof said port.` l

A heating furnace jlforv viscid material having a heating chamber-andl a combustion chamber located therebeneath, -said furnace being further pro-vided with one -or more ports providing communication betweensaid e combustion chamber and said. heating chamber,pipes in-said furnacej chamberv for the circulation of said-material,v saidf pipes lbei-ng located Vin banks at each side of said combustion ports' to .forma clear chamber in alignment withv said ports, whereby saidpipes ad-' jacent said clear chamber will be subjected to thedirect radiant heat of said inowing gases without contact therewith, said furnace .being provided with?anfexhaustttunnel and one or more ports affordingicommunication-betweenV saidjfurnace chamber and said tunnel, said portsy from said combustion arranged .to supply heating gases thereto out of direct contact withfthe pipes adjacent to clear'chamber, whereby said adjacent pipes will be subjectedto thei direct unobstructed radiant heat of saidgases without contact chamber rbeing therewith,'said exhaust ports being located in suchwise askv to eifectaredirection of lsaid .l

gases and circulation thereof-through said pipes after passage through said.' clear cham- 8. Arheating furnace for viscid materials hav'in'ga heating chamber, pipes for the circulation of said material, said pipes being arranged in groups one at each sideof saidfhea'tingchamber toprovide a clear space between,

`means to'supplyheating gases at substantial velocity to said clear space out of direct immediate contact withsaid pipes, in a vertical directionywhereby the` pipes adjacent said clear'space will Sbe subjected "to the direct Vravports l .chamber and said tunnel, said ports being so .constructed and arranged'asto effect a redidiant heat :of said inflowing gases without Vcontact therewith, an exhaust tunnel and communicating between said heating rection of said `gases'and circulation thereof through said groups of pipes after passage of said gasesthrough saidclear space. L

9. AV heating furnace for viscid materials having a heatingl chamber, pipes for the circulation of said material,- said pipes being arranged in groups one vat yeach side of Sad heatingchamber, to provide a clear space bei Y tween,means to supply heating gases at substantial velocity to saidclear space out of direct immediate contactwith said pipes `in a vertical direction, whereby the pipes vadjacent said clear spacewill be subjected to the direct radiant heat of said inflowing lgases without contact therewith, exhaust tunnels located one beneath each of said groups ofy pipes and ports communicating between said heating chamber andsaid tunnels, said ports being so constructed and arranged as to effect a redirection of said gases and circulation thereof through said groups of pipes after passage of said gases through said clear space, said furnace being Eprovided with an exhaust passage communicating with said tunnels.

10. A heating furnace for viscid materials having a-heating chamber, pipes for the circulation of said'material, said pipes being arhe'atingchamber toprovide a clear space be- 5 tween, meansto supply heating gases at substantial vvelocity to ysaid clear space outof di# rect immediate contact vwith said pipes, in a www? contact therewith, *an outlet, at o-r near the -bottom of said chamber adjacent said group of pipes and spaced from said inlet, s'ai'doutlet being constructed and arranged to effect a redirection 'of said gases and circulation.VN

thereof through said pipes yafter passage through said clear space, and means to-control the amount of gases discharged fromsaid chamber through saidroutlet. i

In testimony whereof, I name to this specication.

HENRYA. DRFEEIN.

have signed I Yranged in groups one Yat each sideof said v i Y ico verticaldire'ction, whereby the pipes' adjacent ing with said tunnels, said'ports being so constructed and arrangedfas-toeifect a redirection of` said gases and` circulation thereof through said groups of pipes after passage of said gases through said clear space, and means e tol regulate the amount of gases flowing from said tunnels into said passage.`

11. A heating furnace for viscid material having a heating chamber, a group ofspacedV circulating pipes :in said chamber for the passage of. said material, said .chamber beingr provided with a clear space at one side of said pipes, an inlet at or near thebottom of said-chamber to supply heating gases to'said space in a vertical direction at substantialV velocityand out of direct contact with the' pipesadjacentsaidspace whereby said last named pipes will be subjectedto the direct radiantiheat of the incoming gaseswithout 

